KR20210127172A - Method and apparatus for making ternary cathode material - Google Patents

Abstract

A method for producing a ternary cathode material (130) for a lithium battery by roasting a raw material (110) in a roasting kiln (120) provided therein, wherein a gas component (a) of the atmosphere into the roasting kiln (120) An apparatus for manufacturing a ternary cathode material (130), as well as a method in which the implantation of is controlled in a closed loop controlled manner based on at least one process influencing parameter being measured.

Description

Method and apparatus for making ternary cathode material

The present invention relates to a method and apparatus for producing a ternary cathode material for a lithium battery by roasting the raw material in a roasting kiln.

The market for electric and hybrid vehicles is growing rapidly. This creates an increasing demand for lithium or lithium ion batteries typically used in the automotive industry. A lithium battery includes, among other components, a cathode material and an anode material. The processes for making these materials and their components typically use gases such as oxygen, nitrogen and argon.

Due to the demand for long-distance electric and hybrid vehicles, there is a need in the lithium battery industry to find higher energy ratio cathode materials and corresponding solutions. So-called ternary cathode materials with higher energy densities have become a trend in the industry. Such ternary cathode materials for lithium batteries are typically prepared by roasting the raw material in a roasting kiln providing an atmosphere within the roasting kiln.

The present invention aims to improve the possibility of obtaining a product from raw materials roasted in a roasting kiln and thus to provide a better lithium battery.

This object is achieved by providing a method and apparatus according to the independent claims.

The method according to the present invention is suitable for producing a ternary cathode material for a lithium battery (lithium ion battery) by roasting the raw material in a roasting kiln provided therein with an atmosphere. A continuous roller hearth kiln or a pusher kiln is preferably used as the roasting kiln. Typical and preferred ternary cathode materials are nickel cobalt manganese and nickel cobalt aluminum. Typical temperatures used for such roasting processes are between 700° C. and 1000° C., and the roasting process typically lasts between 10 and 18 hours.

The chemical reaction that occurs in the roasting process can be described by the following formula, where M represents Ni (nickel), Mn (manganese), Co (cobalt) and/or Al (aluminum):

M(OH) ₂ + 0.5 Li ₂ CO ₃ + 0.25 O ₂ = LiMO ₂ + 0.5 CO ₂ + H ₂ O

M(OH) ₂ + LiOH.H ₂ O + 0.25 O ₂ = LiMO ₂ + 2.5 H ₂ O

In particular, oxygen plays an important role in the process as it helps oxidize, ^{for example, Ni 2+} to Ni ^{3+ .} However, Ni ³⁺ faces the problem of decomposition if the temperature prevailing in the roasting kiln is too high. Thus, the ternary cathode material can easily decompose at high or too high temperatures. Therefore, the roasting process should keep its temperature as low as possible to ensure that ^{Ni 3+ does not undergo decomposition.} A further objective is to provide a uniform temperature distribution and/or a uniform atmosphere inside the kiln so that all raw materials in the kiln are exposed to the same process conditions.

According to the invention, the injection of the gas component, preferably oxygen, of the atmosphere into the roasting kiln is controlled in a closed-loop control manner, ie by closed-loop control, on the basis of the at least one process-influencing parameter measured. In particular, closed-loop control is performed automatically by a control module or the like.

Such process influencing parameters may be any parameters affecting the process. Preferably, the at least one process influencing parameter is a parameter characterizing the raw material, such as a particular composition of the raw material; and/or parameters characterizing the atmosphere, such as the gas components present (such as oxygen, carbon dioxide) and their specific ratio or humidity; and/or parameters characterizing the ternary cathode material, such as its specific composition. In order to measure such parameters, corresponding measuring and/or analysis means may be provided in suitable locations.

Advantageously, a gas injection lance is used for the injection of gas components in one or more zones of the roasting kiln. In particular, the gas injection lance is installed or provided on the ceiling or side wall of the roasting kiln. For more than one zone, one of those gas injection lances may be used for each zone. Also, two or more of those gas injection lances may be used in one or more of the zones. Zones of a roasting kiln may be defined based on zones or zones having different process parameters, such as different zones having different temperatures and/or different speeds for moving raw material through the roasting kiln. Such gas injection lances allow for very precise injection and, as a result, a very uniform contribution of gas within the roasting kiln. However, zones may also be assigned to saggars present in the roasting kiln.

For example, a gas injection lance (or each of several gas injection lances) is provided with one or more nozzles having a predetermined orientation. The predetermined direction may preferably be selected from 0° to 90° with respect to the longitudinal axis of the roasting kiln. In that way, it is possible to cause the atmosphere and in particular the injected gas to move towards a desired direction. Also, turbulence or gas flow movements may thereby be generated.

Preferably, the gas component is provided to the gas injection lance at a pressure of 0.5 bar to 10 bar. This allows to select the speed at which the gas leaves the lance or its nozzle. For example, the speed can reach the speed of sound.

Advantageously, at least a portion of the gas injection lance (or each of the several lances) is made of a material such as steel (stainless steel or heat-resistant alloy, etc.) coated with a ceramic, or the gas injection lance (or each of the several lances) is made of ceramic. Such ceramics, in particular in the case of their use as coatings, are particularly _{Al 2} O ₃ , ZrO, SiC, etc. with very high purity, which may not allow any direct contact of materials such as steel or other metal parts with the atmosphere in the kiln.

The proposed method allows a very uniform exposure of the raw materials to the oxygen required for such a process. For example, in the case of several saggars present in a kiln, all saggars can be exposed to sufficient oxygen. However, without such a method, less contact of the raw material with oxygen was seen in the inner saggars. In contrast, the raw material of the outer saggars appeared to have a better chance for contact with oxygen. Therefore, the roasting quality was not good for the raw material in the inner saggars or saggar line. The layer thickness of the raw material had to be made very thin. These disadvantages can be overcome by the proposed method.

The proposed method also allows to improve the quality of the ternary cathode material for lithium battery manufacturing, thereby improving the quality stability of such a ternary cathode material, keeping the oxygen level (or the level of other gas components) stable It meets the roasting process requirements for specific materials within each section of the kiln. In addition, the possibility of improving the manufacturing capacity is provided. Energy consumption and flow gas volume can be reduced.

It should be noted that the proposed method can also be used to convert other raw materials into corresponding products by such a roasting kiln. For example, a lithium iron phosphate (LFP) cathode material, or a graphene anode material may be prepared from the corresponding raw material.

A further object of the present invention is an apparatus for producing a ternary cathode material for a lithium ion battery, comprising a roasting kiln in which an atmosphere and raw materials to be roasted can be provided. The apparatus also comprises injection means for injection of the gas component of the atmosphere into the roasting kiln, and control means for controlling the injection of the gas component in a closed loop control manner based on the measured at least one process influencing parameter. Measuring means may be provided for measuring such parameters. The injection means preferably comprises at least one gas injection lance, the gas injection lance having a nozzle at its end, the nozzle being 0° to 90°, preferably 20° to 70° relative to the longitudinal axis of the gas injection lance. has a predetermined orientation of °. Preferably, the apparatus is configured to carry out the method according to the invention.

With regard to further embodiments and advantages of the device according to the invention, reference is made to the above description in order to avoid repetition.

The present invention will now be further described with reference to the accompanying drawings, which show a preferred embodiment.

1 schematically shows a device by which the method of the invention can be advantageously implemented;
Fig. 2 schematically shows a gas injection lance as part of the apparatus of Fig. 1 in more detail;
Fig. 3 shows the gas injection lance of Fig. 2 in a different view;

1 , a device 100 according to the invention in a preferred embodiment is shown. Such an apparatus may be used and configured to perform a method according to the invention. In the following, an apparatus and a corresponding method will be described together.

The apparatus 100 comprises a roasting kiln 120 , for example in the form of a continuous roller furnace kiln, whereby raw material 110 is roasted to obtain a ternary cathode material 130 . The raw material 110 may be supplied into the roasting kiln 120 , and in the roasting kiln 120 , the raw material may be moved to, for example, saggar lines 125 .

During the time the raw material is moving inside the roasting kiln 120 , the raw material is roasted and undergoes conversion to the desired ternary cathode material 130 . In the context of transformation, this is referred to as the aforementioned recipe. After the raw material is completely converted at the distal end of the roasting kiln 120 , the product, namely the ternary cathode material 130 , can be taken out of the kiln.

In the roasting kiln 120 , an atmosphere is provided, which contains different gas components such as (pure or near pure) oxygen, air and flue gases. By way of example, oxygen or an oxygen feed is designated a, an air or air feed is designated b, and a flue gas (such as nitrogen) or flue gas feed is designated c.

These gas components (a, b, c) are supplied to the inside of the roasting kiln 120 through the control means or control module (150). By means of the control module 150, the respective flows of those gas components can be controlled.

In the embodiment shown, oxygen a is introduced into the roasting kiln 120 via three gas injection lances 140 which are provided in different zones 126 along the path of movement of the raw material within the roasting kiln 120 for example. 120) is supplied. The control module 150 may be configured such that the oxygen a (ie, its mass flow) provided to the control module may be distributed at a predetermined variable ratio between these three gas injection lances 140 .

Different parameters affecting the roasting process are measured in order to determine on the one hand the currently preferred ratio of oxygen flow between the gas injection lances 140 and on the other hand the absolute mass flow of oxygen for each of the gas injection lances 140 . can be fed to the control module to establish closed loop control.

By way of example, measuring and/or analyzer means 111 for measuring or analyzing a parameter characterizing the raw material 110 , measuring and/or analyzer means 121 for measuring or analyzing a parameter characterizing the atmosphere, and 3 Measurement and/or analyzer means 131 for measuring or analyzing the raw cathode material 130 are provided. Each of these means may supply measurement or analysis results in the form of a signal to the control module 150 so that these results can be used to alter (or maintain) oxygen flow.

It should also be noted that the flows of air (b) and/or flue gas (c) can be varied in the same way if necessary or convenient. In addition, also the pressure of the roasting kiln atmosphere can be measured and controlled.

In FIG. 2 , a gas injection lance 140 that is part of the apparatus 100 of FIG. 1 is shown in perspective in greater detail. In FIG. 3 , the gas injection lance 140 of FIG. 2 is shown in cross-section.

From the left end, oxygen can be supplied to the gas injection lance 140 . As this lance 140 is transferred into the roasting kiln 120 , oxygen may be delivered into the kiln. At the right or inlet end 141 , the gas injection lance 140 includes a nozzle 142 . This nozzle 142 is provided in the form of a channel having an angle with respect to the longitudinal direction or axis of the gas injection lance 140 (and preferably also with respect to other directions).

With such nozzles (several nozzles may also be provided in the lance), oxygen may be injected into the roasting kiln at a desired rate and in a desired direction. The final direction in which oxygen is injected is determined by the orientation of the nozzles (or channels) 142 in the gas injection lance 140 and the orientation in which the gas injection lances 140 are arranged in the roasting kiln 120 .

As mentioned above, the gas injection lance 140 may be made of a ceramic material or made of steel (or stainless steel) covered with such a ceramic. Basically, only the part of the lance to be placed inside the roasting kiln needs to be covered or made of ceramic or other similar material to avoid damage due to oxidation.

By providing a desired number of such lances and providing these lances in a desired orientation (relative to their nozzles), a very uniform distribution of oxygen within the roasting kiln 120 or its atmosphere can be achieved. As a result, a ternary cathode material can be manufactured in a better and more efficient manner.

Claims (13)

A method for producing a ternary cathode material (130) for a lithium battery by roasting a raw material (110) in a roasting kiln (120) provided therein, an atmosphere comprising:
Method, characterized in that the injection of the gaseous component (a) of the atmosphere into the roasting kiln (120) is controlled in a closed loop control manner on the basis of at least one process influencing parameter measured. The method according to claim 1, wherein a gas injection lance (140) is used for the injection of the gaseous component (a) in one or more zones (126) of the roasting kiln (120). 3. The method according to claim 2, wherein the gas injection lance (140) is provided with one or more nozzles (142) having a predetermined orientation. The method according to claim 3 , wherein the predetermined direction is selected from 0° to 90° with respect to the longitudinal axis of the roasting kiln ( 120 ). 5. The method according to any one of claims 2 to 4, wherein the gas component is provided to the gas injection lance (140) at a pressure of 0.5 bar to 10 bar. Method according to any one of claims 2 to 5, wherein the gas injection lance (140) is made, at least in part, of a ceramic coated material or made of a ceramic. 7. The method according to any one of the preceding claims, wherein the at least one process influencing parameter is selected from parameters characterizing the raw material (110) and/or the atmosphere and/or the ternary cathode material (130). How to become. 8. The method according to any one of the preceding claims, wherein the gas component (a) of the atmosphere is oxygen. 9. The method according to any one of the preceding claims, wherein the ternary cathode material (130) comprises nickel cobalt manganese or nickel cobalt aluminum. 10 . The method according to claim 1 , wherein a continuous roller hearth kiln or a pusher kiln is used as the roasting kiln ( 120 ). An apparatus (100) for producing a ternary cathode material (130) for a lithium ion battery, comprising a roasting kiln (120) into which an atmosphere and a raw material (110) to be roasted can be provided, the apparatus (100) comprising:
injection means (140) for injection of the gas component (a) of the atmosphere into the roasting kiln (120), wherein the gas component (a) in a closed loop control manner based on at least one process influencing parameter measured ), the device (100) characterized in that it further comprises control means (150) for controlling the injection. 12. The gas injection lance according to claim 11, wherein said injection means (140) comprises at least one gas injection lance, said gas injection lance having a nozzle at its end, said nozzle being between 0[deg.] and with respect to the longitudinal axis of said gas injection lance. Apparatus ( 100 ) having a predetermined orientation of 90°, preferably 20° to 70°, and/or wherein the gas injection lance is installed on the ceiling or sidewall of the roasting kiln. Device ( 100 ) according to claim 11 , further configured to perform the method according to claim 1 .

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